Enter your pool volume (in gallons), current salt level (in ppm), and your target salt level to find out exactly how many pounds of salt to add to your pool. The Pool Salt Calculator uses the standard salinity formula to give you a precise salt addition amount, keeping your saltwater pool in the ideal 2,700–3,400 ppm range.
Salt to Add
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Salt to Add (kg)
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Current Salt Status
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40 lb Bags Needed
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50 lb Bags Needed
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The amount of salt depends on your pool's volume and current salt level. The formula is: Salt to Add (lbs) = Pool Volume (gallons) × 8.35 × (Target ppm − Current ppm) ÷ 1,000,000. For a 20,000-gallon pool starting at 0 ppm, you'd need roughly 534 lbs of salt to reach 3,200 ppm.
The ideal salt concentration is 3,200 ppm (parts per million). An acceptable range is 2,700–3,400 ppm for most saltwater chlorine generators. Levels outside this range can reduce chlorinator efficiency or cause equipment damage.
If salt is below 2,700 ppm, your chlorine generator won't produce enough chlorine to sanitize the pool effectively. This can lead to algae growth, cloudy water, and unsafe swimming conditions. Your chlorinator may also display a low-salt warning or shut off entirely.
Salt levels above 3,400–4,000 ppm can cause corrosion of pool equipment, surfaces, and metal fittings. Very high concentrations (above 5,000 ppm) may make the water taste noticeably salty. The only way to reduce salt is to partially drain the pool and refill with fresh water.
Enter your pool's total volume in gallons, your current measured salt level in ppm (test with a salt strip or digital meter), and your target salt level (default 3,200 ppm). The calculator instantly shows how many pounds and kilograms of salt to add, plus the number of standard 40 lb or 50 lb bags you'll need.
Use 99.8% pure sodium chloride (NaCl) — either pool-grade salt, solar salt, or food-grade salt. Avoid rock salt, which may contain impurities that cloud the water. Do not use iodized table salt, as the additives can stain pool surfaces and damage equipment.
You can typically swim 20–30 minutes after adding salt, once it has dissolved and circulated. Run your pool pump for at least 24 hours after adding salt to ensure it fully dissolves and the concentration is even throughout the pool.
Test your pool's salt level at least once a month during swim season, or whenever your saltwater chlorinator displays a warning. Salt evaporates slowly, but heavy rain, backwashing, and splashing out water can dilute levels. Top up as needed based on calculator results.